This invention relates to an improved lamp for use in vehicles and beacon lights and so forth. The conventional lamps for use as beacon lights or for illumination, especially in vehicles comprise a housing containing a bulb, an inner lens having so-called frenel lens which converts the light radiated from the bulb into parallel rays of light, a condenser lens consisting of a plurality of convex lenses on the surface facing the bulb and concave lens on the opposite surface. The condenser lens condenses the parallel rays of light into a plurality of beams consisting of parallel rays of light. An outer lens having pervious portions receives light corresponding to the beams radiated from the condenser lens. In this case, the outer lens is usually a flat plate.
In the lamp of this kind, from the nature of it, a high degree of illumination is required, however the lamps having such construction as mentioned above have drawbacks. That is, the light radiated from the outer lens is apt to have an uneveness in its brightness in the direction of the beams, thus reducing the effectiveness of the illumination of the lamp.